Biological and Medicinal Chemistry

Molecular Simulations suggest Vitamins, Retinoids and Steroids as Ligands binding the Free Fatty Acid Pocket of SARS-CoV-2 Spike Protein


Following our recent identification of a fatty acid binding site in the SARS-CoV-2 spike protein (Toelzer et al., Science eabd3255 (2020)), we investigate the binding of linoleate and other potential ligands at this site using molecular dynamics simulations. The results support the hypothesis that linoleate stabilises the locked form of the spike, in which its interaction interface for the ACE2 receptor is occluded. The simulations indicate weaker binding of linoleate to the partially open conformation. Simulations of dexamethasone bound at this site indicate that it binds similarly to linoleate, and thus may also stabilize a locked spike conformation. In contrast, simulations suggest that cholesterol bound at this site may destabilize the locked conformation, and in the open conformation, may preferentially bind at an alternative site in the hinge region between the receptor binding domain and the domain below, which could have functional relevance. We also use molecular docking to identify potential ligands that may bind at the fatty acid binding site, using the Bristol University Docking Engine (BUDE). BUDE docking successfully reproduces the linoleate complex and also supports binding of dexamethasone at the spike fatty acid site. Virtual screening of a library of approved drugs identifies vitamins D, K and A, as well as retinoid ligands with experimentally demonstrated activity against SARS-CoV-2 replication in vitro, as also potentially able to bind at this site. Our data suggest that the fatty acid binding site of the SARS-CoV-2 spike protein may bind a diverse array of candidate ligands. Targeting this site with small molecules, including dietary components such as vitamins, which may stabilise its locked conformation and represents a potential avenue for novel therapeutics or prophylaxis for COVID-19.

Version notes

This is the first version uploaded to chemRxiv


Thumbnail image of SARS2-spike_FA-site_simulations_docking-FDA_db_Shoemark-Colenso_et-al.pdf
download asset SARS2-spike_FA-site_simulations_docking-FDA_db_Shoemark-Colenso_et-al.pdf 2 MB [opens in a new tab]

Supplementary material

Thumbnail image of Table_S1_FA_binding_site_SARS2-spike.pdf
download asset Table_S1_FA_binding_site_SARS2-spike.pdf 0.45 MB [opens in a new tab]
Table S1 FA binding site SARS2-spike
Thumbnail image of Table_S2_FA_binding_site_SARS2-spike.pdf
download asset Table_S2_FA_binding_site_SARS2-spike.pdf 0.52 MB [opens in a new tab]
Table S2 FA binding site SARS2-spike
Thumbnail image of Table_S3_FA_binding_site_SARS2-spike.pdf
download asset Table_S3_FA_binding_site_SARS2-spike.pdf 0.67 MB [opens in a new tab]
Table S3 FA binding site SARS2-spike